330 BULLETIN OF THE 



lagern. Dieses Resultat bin ich nunmehr ini Stande auf Limnseus 

 auszudehnen, und so diirfte wohl der Nachweis ahnlicher Strahlen fur 

 die ubrigen Thiere einen Riickschluss auf die amoboide Beweglichkeit 

 der Furchungskerne gestatten." 



The close relationship between Limax and Lymnseus allows me to speak 

 with more confidence than might otherwise be the case. It is to be 

 noticed that the phenomena which Brandt interprets as due to extensive 

 amoeboid movements of the nucleus, are thus explained on what seems 

 to be very insufficient evidence. The inference drawn from the fact, 

 that in place of distinct nuclei there are to be found only irregular and 

 often indistinct figures which imdergo change of form and position, is 

 far from satisfactory. Further, proof is not produced that the irregular 

 amoeboid figures are nuclear structures. Nor is his position strength- 

 ened when it is subsequently maintained that the so-called nucleus is, 

 in reality, the cell ; for enough is known of this so-called nucleus to 

 warrant the expectation that it will respond in a definite way to various 

 reagents. These, however, the author does not seem to have employed, 

 and it must be largely due to this fact, that his observations present 

 with undue prominence certain features of cell activity and entirely 

 ignore fundamental internal changes. If we both arrive at the same 

 negative conclusion respecting the complete dissolution and disappearance 

 of the germinative vesicle and its descendants (nuclei), it is nevertheless 

 from quite different data. The motion which results from the amoe- 

 boid character of the nucleus is not competent to explain its admitted 

 absence (Brandt, 77^, p. 592 and Fig. 7), but on the contrary should 

 make the moving masses — the pseudopodia — more readily discernible. 

 Even without the evidence which other methods of research bring to 

 bear on this question, I should agree with Warneck ('50, p. 115), who has 

 observed similar phenomena and referred them to an unequal distribu- 

 tion of the elementary corpuscles of the yolTc. If it be objected that 

 he makes no attempt to explain the cause of the unequal distribution of 

 these corpuscles, and that consequently he may not be cited as conflict- 

 ing with the amoeboid theory, I reply that he does not anywhere admit 

 such radical changes in the form of the nucleus as Brandt maintains, and 

 that some of his figures appear to me quite inexplicable under that theory. 

 I would especially call attention to his Tab. IV. Fig. 10'' (compare with 

 the text at p. 125), where the inequalities in the distribution of the 

 corpuscles are as conspicuously represented as in any of his figures, and 

 where the nuclei (two pronuclei) are represented with the greatest distinct- 

 ness as sharply defined spheroidal bodies. 



